Calamus deerratus fibre reinforced natural rubber vulcanizates

This research study investigates the potentials of Calamus deerratus fibre (CDF) as a reinforcing filler in natural rubber, Standard Nigerian Rubber (SNR10)   vulcanizates. The Calamus deerratus was cut, dried, pulverized, characterized and incorporated into the natural rubber compounds and the effects on the cure  characteristics and physico-mechanical properties of the CDF-reinforced natural rubber vulcanizates were determined. The results of the analyses, in comparison with a standard carbon black, CB(N330)-filled vulcanizates showed that the CDF manifested a reinforcing effect on the SNR10 vulcanizates but inferior to carbon black, N330-filled vulcanizates. The maximum torque, abrasion resistance, modulus, specific gravity and hardness increased while the scorch time, cure time,   elongation at break and rebound resilience decreased with increasing filler content. The cure time and scorch time were however higher in CDF-filled SNR10   vulcanizates compared to those filled with carbon black, N330. Tensile strengths of CB(N330)- and CDF- filled vulcanizates increased to optimum levels at 40 phr  and 30 phr respectively and decreased with increasing filler content. The results however showed that CDF imparted lower reinforcing potential as shown by the   lower tensile strength, abrasion resistance and modulus. The hardness results of the CDF-filled vulcanizates showed slight superiority over that of CB(N330)-filled vulcanizates.Keywords: Natural rubber, Calamus deerratus, fillers, reinforcement and vulcanizates

The reinforcing potentials of Velvet tamarind seed shell as filler in natural rubber compounds

This work focused on the development of a reinforcing filler from renewable natural plant resources as part of the ongoing search for environmental friendly fillers that will substitute synthetic reinforcing fillers such as carbon black and silica in rubber manufacturing. The cure characteristics, physico-mechanical and equilibrium swelling properties of natural rubber, Standard Nigerian Rubber (SNR10) vulcanizates separately filled with commercial grade carbon black (CB), N330 and pulverized natural plant material, Velvet tamarind (VT), seed shell were investigated. The results of the analyses showed that the scorch and cure times decreased while the maximum torques increased with increasing filler loading for both filled-SNR10 vulcanizates. The tensile strengths of both VT-filled and CB (N330) filled-SNR10 vulcanizates increased to 30 phr and 40 phr respectively and decreased with increasing filler loading. The modulus at 100% strain, specific gravity, abrasion resistance and hardness increased while elongation at break, equilibrium swelling and rebound resilience decreased with increasing filler loading for both filled-SNR10 vulcanizates. The results showed that Velvet tamarind seed shell manifested a reinforcing effect on the SNR10 compounds but lower than that of CB (N330) filler.Keywords: Natural rubber, fillers, reinforcement and vulcanizate properties

Cure Characteristics and Physico-Mechanical Properties of Natural Rubber Filled with the Seed Shells of Cherry ( Chrysophyllum Albidum )

The cure characteristics and the physico-mechanical properties of natural rubber, standard Nigerian rubber, SNR10 filled with cherry seed shell (CSS) and standard carbon black CB (N330) were determined. The results showed that the scorch, cure times and the maximum torque gradually increased with increasing filler content for CSS-filled natural rubber, but in the case of CB-filled natural rubber, the scorch and the cure times decreased while the maximum torque increased with increasing filler content. The tensile strength of both CSS and CB-filled vulcanizates increased to a maximum at 40 phr filler content before declining. The moduli (M100 and M300), specific gravity (S.G), hardness and abrasion resistance increased while the elongation at break and Dunlop resilience decreased with increasing filler content for both vulcanizates. The locally sourced CSS filler, had a lower reinforcement properties compared to the CB (N330) filler, probably due to its higher moisture content and larger particle size

The practice of hepatocellular cancer surveillance in Nigeria

Background: Hepatocellular cancer is a disease of global and public health importance due to the widespread distribution of risk factors and associated high case fatality. Hepatocellular Cancer (HCC) in Sub-Saharan Africa is commonly seen among the younger age groups (<45 years) who present mostly in the terminal stage, when the disease is not amenable to any curative therapy. Hepatocellular Carcinoma surveillance employs the use of simple, cheap and readily available investigations, to detect early curable cancer in individuals with risk factors for HCC.Objectives:The aim of this study is to assess the practice of hepatocellular cancer screening among physicians.Methodolgy:This is a nationwide online survey carried out among physicians who care for patients with HCC. A questionnaire was sent out via a web link to all consenting doctors in Nigeria. The responses were collated in a cloud-based application and data was analysed using Epi-info version 20.Results:Atotal of 218 respondents, 142 were males (65.1 %) with a mean age of 37.6 ± 5.7 years. The modal age group was 31-40 years 153 (69.5%). The main factors considered as a hindrance to surveillance were; the cost of the tests (57.7%), failure of return of patients (50.5%) and not being aware of a surveillance program (45.2 %). The majority of the respondents were Gastroenterologists and Family Physicians. 54% of the gastroenterologists and 64% of the family physicians have never offered HCC surveillance to their patients.Conclusion:This survey highlights a knowledge gap in HCC surveillance among physicians. There is a need to make HCCsurveillance a daily routine among patients at risk by all physicians. Keywords: Surveillance, Hepatocellular Carcinoma, HBV, HCV, Cancer screening

Cure Characteristics and Physico-Mechanical Properties of Natural Rubber Filled with the Seed Shells of Cherry ( Chrysophyllum Albidum )

The cure characteristics and the physico-mechanical properties of natural rubber, standard Nigerian rubber, SNR10 filled with cherry seed shell (CSS) and standard carbon black CB (N330) were determined. The results showed that the scorch, cure times and the maximum torque gradually increased with increasing filler content for CSS-filled natural rubber, but in the case of CB-filled natural rubber, the scorch and the cure times decreased while the maximum torque increased with increasing filler content. The tensile strength of both CSS and CB-filled vulcanizates increased to a maximum at 40 phr filler content before declining. The moduli (M100 and M300), specific gravity (S.G), hardness and abrasion resistance increased while the elongation at break and Dunlop resilience decreased with increasing filler content for both vulcanizates. The locally sourced CSS filler, had a lower reinforcement properties compared to the CB (N330) filler, probably due to its higher moisture content and larger particle size